Step 1
In a medium heatproof bowl, stir together the red-pepper flakes, soy sauce and sesame oil. Set next to the stovetop.
Step 2
Bring a large pot of salted water to boil. Meanwhile, in a large (12-inch) skillet over medium heat, cook the ½ cup oil, peanuts and orange rind, shaking the pan occasionally, until the peanuts are golden and bubbling, 3 to 5 minutes. Immediately pour the contents of the skillet over the red-pepper mixture (be careful of splattering!) and set aside.
Step 3
Meanwhile, in the same skillet, heat the remaining tablespoon oil over medium-high. Add the chicken and press it down with a wooden spoon into a thin layer. Season with salt and a generous amount of black pepper and cook, without stirring, occasionally pressing the layer of chicken down, until the bottom is browned, 5 to 7 minutes. Break the chicken up into small pieces and cook, stirring occasionally, until cooked through, 1 to 2 minutes more.
Step 4
While the chicken cooks, cook the noodles according to package directions, until chewy but not soft. Drain and toss with a bit of sesame oil.
Step 5
Remove and discard the orange rind from the chile oil. Off the heat, add enough chile oil to coat the chicken and stir, scraping up any browned bits from the pan. Add the noodles and toss, adding more chile oil to fully coat the noodles and chicken. (If you don't use all of the chile oil, you can store it in the refrigerator for 2 weeks in an airtight container.) Top with chives and serve at once.
